Whether you like Miley or not, she is making music that some people like AND is better received than her old music. Yes, many little girls can't stand her anymore, but Miley is evidently making MORE new fans than losing old fans, as shown by higher Billboard and UK rankings. I like her old music more, but I respect her for making music SHE LOVES instead of what Disney tells her to make.
Miley may be trying too hard and pushing the envelop too much, instead of playing safe and following the rules like Selena.
Honestly, if Selena did not date Justin and was not BFF with Taylor, no one would be talking about her. Selena would be another Vanessa Hudgens in which no tabloid really cares.